Jeremy Fitzhardinge wrote:
> I'd noticed that current tip/master hasn't been booting under Xen, and I
> just got around to bisecting it down to this change.
>
> commit 065ae73c5462d42e9761afb76f2b52965ff45bd6
> Author: Suresh Siddha <suresh.b.siddha@intel.com>
>
> x86, cpa: make the kernel physical mapping initialization a two pass sequence
>
> This patch is causing Xen to fail various pagetable updates because it
> ends up remapping pagetables to RW, which Xen explicitly prohibits (as
> that would allow guests to make arbitrary changes to pagetables, rather
> than have them mediated by the hypervisor).
Instead of making init a two pass sequence, to satisfy the Intel's TLB
Application note (developer.intel.com/design/processor/applnots/317080.pdf
Section 6 page 26), we preserve the original page permissions
when fragmenting the large mappings and don't touch the existing memory
mapping (which satisfies Xen's requirements).
Only open issue is: on a native linux kernel, we will go back to mapping
the first 0-1GB kernel identity mapping as executable (because of the
static mapping setup in head_64.S). We can fix this in a different
patch if needed.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Acked-by: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Track the memtype for RAM pages in page struct instead of using the
memtype list. This avoids the explosion in the number of entries in
memtype list (of the order of 20,000 with AGP) and makes the PAT
tracking simpler.
We are using PG_arch_1 bit in page->flags.
We still use the memtype list for non RAM pages.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Do a global flush tlb after splitting the large page and before we do the
actual change page attribute in the PTE.
With out this, we violate the TLB application note, which says
"The TLBs may contain both ordinary and large-page translations for
a 4-KByte range of linear addresses. This may occur if software
modifies the paging structures so that the page size used for the
address range changes. If the two translations differ with respect
to page frame or attributes (e.g., permissions), processor behavior
is undefined and may be implementation-specific."
And also serialize cpa() (for !DEBUG_PAGEALLOC which uses large identity
mappings) using cpa_lock. So that we don't allow any other cpu, with stale
large tlb entries change the page attribute in parallel to some other cpu
splitting a large page entry along with changing the attribute.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: arjan@linux.intel.com
Cc: venkatesh.pallipadi@intel.com
Cc: jeremy@goop.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Interrupt context no longer splits large page in cpa(). So we can do away
with cpa memory pool code.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: arjan@linux.intel.com
Cc: venkatesh.pallipadi@intel.com
Cc: jeremy@goop.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
No alias checking needed for setting present/not-present mapping. Otherwise,
we may need to break large pages for 64-bit kernel text mappings (this adds to
complexity if we want to do this from atomic context especially, for ex:
with CONFIG_DEBUG_PAGEALLOC). Let's keep it simple!
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: arjan@linux.intel.com
Cc: venkatesh.pallipadi@intel.com
Cc: jeremy@goop.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Don't use large pages for kernel identity mapping with DEBUG_PAGEALLOC.
This will remove the need to split the large page for the
allocated kernel page in the interrupt context.
This will simplify cpa code(as we don't do the split any more from the
interrupt context). cpa code simplication in the subsequent patches.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: arjan@linux.intel.com
Cc: venkatesh.pallipadi@intel.com
Cc: jeremy@goop.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
In the first pass, kernel physical mapping will be setup using large or
small pages but uses the same PTE attributes as that of the early
PTE attributes setup by early boot code in head_[32|64].S
After flushing TLB's, we go through the second pass, which setups the
direct mapped PTE's with the appropriate attributes (like NX, GLOBAL etc)
which are runtime detectable.
This two pass mechanism conforms to the TLB app note which says:
"Software should not write to a paging-structure entry in a way that would
change, for any linear address, both the page size and either the page frame
or attributes."
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: arjan@linux.intel.com
Cc: venkatesh.pallipadi@intel.com
Cc: jeremy@goop.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Export set_memory_ro() and set_memory_rw() calls for use by drivers that need
to have more debug information about who might be writing to memory space.
this was initially developed for use while debugging a memory corruption
problem with e1000e.
Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
They were already called once in arch/x86/kernel/setup.c - we don't need to call them again.
fixes:
http://bugzilla.kernel.org/show_bug.cgi?id=11485
Signed-off-by: Alex Nixon <alex.nixon@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
They were already called once in arch/x86/kernel/setup.c - we don't need to call them again.
Signed-off-by: Alex Nixon <alex.nixon@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The CPA test code uses _PAGE_UNUSED1, so make sure its obvious.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Fix the start addr for free_memtype calls in the error path.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Acked-by: Rene Herman <rene.herman@keyaccess.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
early_io{re,un}map() are __init and hence can't be called from __meminit
functions.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
While I don't have a hotplug capable system at hand, I think two issues need
fixing:
- pud_phys (in kernel_physical_ampping_init()) would remain uninitialized in
the after_bootmem case
- the locking done just around phys_pmd_{init,update}() would leave out pgd
updates, and it was needlessly covering code portions that do allocations
(perhaps using a more friendly gfp value in alloc_low_page() would then be
possible)
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Actually, might as well simply reconstruct the memtype list at free time
I guess. How is this for a coalescing version of the array functions?
Compiles, boots and provides me with:
root@7ixe4:~# wc -l /debug/x86/pat_memtype_list
53 /debug/x86/pat_memtype_list
otherwise (down from 16384+).
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The new set_memory_array_{uc,wb}() pass virtual addresses to
{reserve,free}_memtype() it seems.
Signed-off-by: Rene Herman <rene.herman@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
We changed the interface of some pageattr, this patch makes
pageattr-test compile.
Signed-off-by: Dave Airlie <airlied@gmail.com>
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Add array interface APIs of pageattr. page based cache flush is quite
slow for a lot of pages. If pages are more than 1024 (4M), the patch
will use a wbinvd(). We have a simple test here (run a 3d game - open
arena), nearly all agp memory allocation are small (< 1M), so suppose
this will not impact runtime performance.
Signed-off-by: Dave Airlie <airlied@gmail.com>
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
All kernel mappings like ioremap(), etc uses UC_MINUS as the type. /dev/mem
mappings with /dev/mem being opened with O_SYNC however was using UC,
resulting in a conflict with /dev/mem mmap failing. This seems to be
affecting some apps (one being flashrom) which are using O_SYNC and which were
working before.
Switch /dev/mem with O_SYNC also to UC_MINUS.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Big thinko in pat memtype tracking code. reserve_memtype should be called
with physical address and not virtual address.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
WARNING: vmlinux.o(.text+0x180af): Section mismatch in reference from the function leave_uniprocessor() to the function .cpuinit.text:cpu_up()
The function leave_uniprocessor() references
the function __cpuinit cpu_up().
This is often because leave_uniprocessor lacks a __cpuinit
annotation or the annotation of cpu_up is wrong.
leave_uniprocessor calls cpu_up only when CONFIG_HOTPLUG_CPU is set,
so it can be safely annotated as __ref
Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Cc: Pekka Paalanen <pq@iki.fi>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Pekka Paalanen <pq@iki.fi>
Booting kernel with vmalloc=[any size<=16m] will oops on my pc (i386/1G memory).
BUG_ON in arch/x86/mm/init_32.c triggered:
BUG_ON((unsigned long)high_memory > VMALLOC_START);
It's due to the vm area hole.
In include/asm-x86/pgtable_32.h:
#define VMALLOC_OFFSET (8 * 1024 * 1024)
#define VMALLOC_START (((unsigned long)high_memory + 2 * VMALLOC_OFFSET - 1) \
& ~(VMALLOC_OFFSET - 1))
There's several related point:
1. MAXMEM :
(-__PAGE_OFFSET - __VMALLOC_RESERVE).
The space after VMALLOC_END is included as well, I set it to
(VMALLOC_END - PAGE_OFFSET - __VMALLOC_RESERVE)
2. VMALLOC_OFFSET is not considered in __VMALLOC_RESERVE
fixed by adding VMALLOC_OFFSET to it.
3. VMALLOC_START :
(((unsigned long)high_memory + 2 * VMALLOC_OFFSET - 1) & ~(VMALLOC_OFFSET - 1))
So it's not always 8M, bigger than 8M possible.
I set it to ((unsigned long)high_memory + VMALLOC_OFFSET)
4. the VMALLOC_RESERVE is an unused macro, so remove it here.
Signed-off-by: Dave Young <hidave.darkstar@gmail.com>
Cc: akpm@linux-foundation.org
Cc: hidave.darkstar@gmail.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Use WARN() instead of a printk+WARN_ON() pair; this way the message
becomes part of the warning section for better reporting/collection.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: akpm@linux-foundation.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Rene Herman reported significant Xorg startup/shutdown slowdown due
to PAT. It turns out that the memtype list has thousands of entries.
Add cached_entry to list add routine, in order to speed up the
lookup for sequential reserve_memtype calls.
Reported-by: Rene Herman <rene.herman@keyaccess.nl>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (32 commits)
x86: add MAP_STACK mmap flag
x86: fix section mismatch warning - spp_getpage()
x86: change init_gdt to update the gdt via write_gdt, rather than a direct write.
x86-64: fix overlap of modules and fixmap areas
x86, geode-mfgpt: check IRQ before using MFGPT as clocksource
x86, acpi: cleanup, temp_stack is used only when CONFIG_SMP is set
x86: fix spin_is_contended()
x86, nmi: clean UP NMI watchdog failure message
x86, NMI: fix watchdog failure message
x86: fix /proc/meminfo DirectMap
x86: fix readb() et al compile error with gcc-3.2.3
arch/x86/Kconfig: clean up, experimental adjustement
x86: invalidate caches before going into suspend
x86, perfctr: don't use CCCR_OVF_PMI1 on Pentium 4Ds
x86, AMD IOMMU: initialize dma_ops after sysfs registration
x86m AMD IOMMU: cleanup: replace LOW_U32 macro with generic lower_32_bits
x86, AMD IOMMU: initialize device table properly
x86, AMD IOMMU: use status bit instead of memory write-back for completion wait
x86: silence mmconfig printk
x86, msr: fix NULL pointer deref due to msr_open on nonexistent CPUs
...
WARNING: vmlinux.o(.text+0x17a3e): Section mismatch in reference from the function set_pte_vaddr_pud() to the function .init.text:spp_getpage()
The function set_pte_vaddr_pud() references
the function __init spp_getpage().
This is often because set_pte_vaddr_pud lacks a __init
annotation or the annotation of spp_getpage is wrong.
spp_getpage is called from __init (__init_extra_mapping) and
non __init (set_pte_vaddr_pud) functions, so it can't be __init.
Unfortunately it calls alloc_bootmem_pages which is __init,
but does it only when bootmem allocator is available (after_bootmem == 0).
So annotate it accordingly.
Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: H. Peter Anvin <hpa@zytor.com>
Jean Delvare's machine triggered this BUG
acpi_os_map_memory phys ffff0000 size 65535
------------[ cut here ]------------
kernel BUG at arch/x86/mm/pat.c:233!
with ACPI in the backtrace.
Adding some debugging output showed that ACPI calls
acpi_os_map_memory phys ffff0000 size 65535
And ioremap/PAT does this check in 32bit, so addr+size wraps and the BUG
in reserve_memtype() triggers incorrectly.
BUG_ON(start >= end); /* end is exclusive */
But reserve_memtype already uses u64:
int reserve_memtype(u64 start, u64 end,
so the 32bit truncation must happen in the caller. Presumably in ioremap
when it passes this information to reserve_memtype().
This patch does this computation in 64bit.
http://bugzilla.kernel.org/show_bug.cgi?id=11346
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Highmem code can leave ptes and tlb entries around for a given page even after
kunmap, and after it has been freed.
>From what I can gather, the PAT code may change the cache attributes of
arbitrary physical addresses (ie. including highmem pages), which would result
in aliases in the case that it operates on one of these lazy tlb highmem
pages.
Flushing kmaps should solve the problem.
I've also just added code for conditional flushing if we haven't got
any dangling highmem aliases -- this should help performance if we
change page attributes frequently or systems that aren't using much
highmem pages (eg. if < 4G RAM). Should be turned into 2 patches, but
just for RFC...
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Introduce two APIs for page attribute. flushing tlb/cache in every page
attribute is expensive. AGP gart usually will do a lot of operations to
change a page to uc, new APIs can reduce flush.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Cc: airlied@linux.ie
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Do we actually want these DirectMap lines in the x86 /proc/meminfo?
I can see they're interesting to CPA developers and TLB optimizers,
but they don't fit its usual "where has all my memory gone?" usage.
If they are to stay, here are some fixes.
1. On x86_32 without PAE, they're not 2M but 4M pages: no need to
mess with the internal enum, but show the right name to users.
2. Many machines can never show anything but 0 for DirectMap1G,
so suppress that line unless direct_gbpages are really enabled.
3. The unit in /proc/meminfo is kB not number of pages: HugePages
messed that up, but they're an example to regret not to follow.
4. Once we use kB, it's easy to see that 1GB has gone missing (which
explains why CONFIG_CPA_DEBUG=y soon wraps DirectMap2M negative):
because head_64.S's level2_ident_pgt entries were not counted.
My fix is not ideal, but works for more and for less than 1G,
and avoids interfering with early bootup pagetable contortions.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
so we don't get warning on 32bit system with 64g RAM or more
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Use WARN() instead of a printk+WARN_ON() pair; this way the message becomes
part of the warning section for better reporting/collection.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: akpm@linux-foundation.org
Cc: arjan@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
fix spinlock recursion in hvc_console
stop_machine: remove unused variable
modules: extend initcall_debug functionality to the module loader
export virtio_rng.h
lguest: use get_user_pages_fast() instead of get_user_pages()
mm: Make generic weak get_user_pages_fast and EXPORT_GPL it
lguest: don't set MAC address for guest unless specified
Out of line get_user_pages_fast fallback implementation, make it a weak
symbol, get rid of CONFIG_HAVE_GET_USER_PAGES_FAST.
Export the symbol to modules so lguest can use it.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Recently I've run a kernel w/o PAT support and wondered why there was
a file "x86/pat_memtype_list" in debugfs. Of course it's empty if PAT
is disabled ... so just get rid of this interface if PAT is disabled.
Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Simon Horman reported that gcc-3.4.x crashes when compiling
pgd_prepopulate_pmd() when PREALLOCATED_PMDS == 0 and CONFIG_DEBUG_INFO
is enabled.
Adding an extra check for PREALLOCATED_PMDS == 0 [which is compiled out
by gcc] seems to avoid the problem.
Reported-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
